BigPatents India

A method for reducing frictional loss in tunnels carrying a fluid flow, the tunnel defining upstream and downstream directions and inlet and outlet ends and having a wall defining a cross section width, the wall having a texture, the method comprising the steps of: introducing a pipe into the tunnel, the pipe having a cross section width which is equal to or somewhat less than the largest cross section width of the tunnel, attaching at least a plurality of points of the pipe to the tunnel wall, and producing a super pressure in the pipe relative to the pipe exterior during flow. (FIG. - 1)